The downfall of CIA Director David Petraeus demonstrates how easy it is for federal law enforcement agents to examine emails and computer records if they believe a crime was committed. With subpoenas and warrants, the FBI and other investigating agencies routinely gain access to electronic inboxes and information about email accounts offered by Google, Yahoo and other Internet providers.

Under the 1986 Electronic Communications Privacy Act, federal authorities need only a subpoena approved by a federal prosecutor - not a judge - to obtain electronic messages that are six months old or older. To get more recent communications, a warrant from a judge is required. Critics want the law updated to reflect changes in technology.